fix(fetch): integration with MockAgent (nodejs#1149)

* fix(fetch): integration with MockAgent

* fix(fetch): integration with MockAgent

* chore: cleanup

* chore: cleaned up the tests

* fix: more tests and headers support

* fix: corrects a syntax error in node 12

* Update lib/mock/mock-utils.js

Co-authored-by: Robert Nagy <[email protected]>

Co-authored-by: Matteo Collina <[email protected]>
Co-authored-by: Robert Nagy <[email protected]>

Author: 3 people

lib/fetch/index.js

@@ -46,6 +46,7 @@ const { kHeadersList } = require('../core/symbols')
 const EE = require('events')
 const { PassThrough, pipeline } = require('stream')
 const { isErrored, isReadable } = require('../core/util')
+const { kIsMockActive } = require('../mock/mock-symbols')
 
 let ReadableStream
 
@@ -1621,7 +1622,7 @@ function httpNetworkFetch (
         path: url.pathname + url.search,
         origin: url.origin,
         method: request.method,
-        body,
+        body: context.dispatcher[kIsMockActive] ? request.body && request.body.source : body,
         headers: request.headersList,
         maxRedirections: 0
       },

lib/mock/mock-utils.js

@@ -1,6 +1,7 @@
 'use strict'
 
 const { MockNotMatchedError } = require('./mock-errors')
+const { kHeadersList } = require('../core/symbols')
 const {
   kDispatches,
   kMockAgent,
@@ -30,8 +31,11 @@ function matchHeaders (mockDispatch, headers) {
   if (typeof headers !== 'object' || typeof mockDispatch.headers !== 'object') {
     return false
   }
+
   for (const [matchHeaderName, matchHeaderValue] of Object.entries(mockDispatch.headers)) {
-    if (!matchValue(matchHeaderValue, headers[matchHeaderName])) {
+    const header = typeof headers.get === 'function' ? headers.get(matchHeaderName) : headers[matchHeaderName]
+
+    if (!matchValue(matchHeaderValue, header)) {
       return false
     }
   }

test/node-fetch/mock.js

@@ -0,0 +1,86 @@
+/* eslint no-unused-expressions: "off" */
+
+// Test tools
+const chai = require('chai')
+
+const {
+  fetch,
+  MockAgent,
+  setGlobalDispatcher,
+  Headers
+} = require('../../index.js')
+
+const { expect } = chai
+
+describe('node-fetch with MockAgent', () => {
+  it('should match the url', async () => {
+    const mockAgent = new MockAgent()
+    setGlobalDispatcher(mockAgent)
+    const mockPool = mockAgent.get('http://localhost:3000')
+
+    mockPool
+      .intercept({
+        path: '/test',
+        method: 'GET',
+      })
+      .reply(200, { success: true })
+      .persist()
+
+    const res = await fetch('http://localhost:3000/test', {
+      method: 'GET'
+    })
+
+    expect(res.status).to.equal(200)
+    expect(await res.json()).to.deep.equal({ success: true })
+  })
+
+  it('should match the body', async () => {
+    const mockAgent = new MockAgent()
+    setGlobalDispatcher(mockAgent)
+    const mockPool = mockAgent.get('http://localhost:3000')
+
+    mockPool
+      .intercept({
+        path: '/test',
+        method: 'POST',
+        body: (value) => {
+          return value === 'request body'
+        }
+      })
+      .reply(200, { success: true })
+      .persist()
+
+    const res = await fetch('http://localhost:3000/test', {
+      method: 'POST',
+      body: 'request body'
+    })
+
+    expect(res.status).to.equal(200)
+    expect(await res.json()).to.deep.equal({ success: true })
+  })
+
+  it('should match the headers', async () => {
+    const mockAgent = new MockAgent()
+    setGlobalDispatcher(mockAgent)
+    const mockPool = mockAgent.get('http://localhost:3000')
+
+    mockPool
+      .intercept({
+        path: '/test',
+        method: 'GET',
+        headers: {
+          'User-Agent': /^undici$/,
+        }
+      })
+      .reply(200, { success: true })
+      .persist()
+
+    const res = await fetch('http://localhost:3000/test', {
+      method: 'GET',
+      headers: new Headers({ 'User-Agent': 'undici' })
+    })
+
+    expect(res.status).to.equal(200)
+    expect(await res.json()).to.deep.equal({ success: true })
+  })
+})